Lightning-arrester.



A. J. WURTS.

LIGHTNING ARRESTER.

APPLICATION FILED SE?T.5, 1905.

Patented Nov. 1, 1910.

Fly. 71

I INVENTOR WlTNESSESI UNITED STATES PATENT oriricn.

ALEXANDER JAY WURTS, OF PITTSBURG, PENNSYLVANIA, ASSIGNQB, 'lO WESTING- HOUSE ELECTRIC 8; MANUFACTURING COMPANY, A C'GR-PORATIQN @F PENNSYL- VANIA.

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Specification of Letters Patent.

Application filed September 5, 1905.

Patented Nov. 1, 1910. Serial No. 277,104.

to provide improved means of the character and for the purpose indicated.

Many of the devices for protecting electric circuits from lightning discharges comprise grounded circuit connections for the distributing conductors that include air spaces or spark gaps across which the static or lightning discharges may occur. In the use of such devices, arcs are frequently formed in the air spaces by the dynamo our- 4 rent that is supplied from the protected circuit after the disruptive discharges take place and various supplementary means have been employed for preventing the formation of such arcs or for causing rupture thereof immediately upon formation. The means which I propose to employ coruprisesn fuse which is destroyed and the supporting means for which may be shattered by the passage of current through or over it, and 1 further provide means tor auton'iatically replacing a destroyed fuse.

F igui'e 1 of the accompanying drawing, is a diagrammatic View of a system embodying my invention. Fig. 2 is a view, partially in side elevation and partially in section, of means for supporting the fuses and for antoinaticallyplacing them in circuit, and Fig.

' 3 is a partial end new of the device shown in l krranged between supply conductors 1 and 2 that may be connected with any suitable source of electrical energy 3 are a plurality of parallel circuits 4, each of which includes a itusc 5 and a pair of serrated terminal pieces 6 and 7 with a spark gap or air space 8 between thernl' Each of the fuses 5 comprises a. strip of ground glass 9 or other similar'insulatmg mater al upon the surface of whicha film or coating 10 of suitable concluding material suchas graphite is a "led, th

e' mass of the conducting material ing so small that. only a negligible amount the ground at G.

of gas or vapor is produced upon its being fused. Whenever the conductors l and 2 become statically charged by lightning or otherwise, discharges occur at one of the spark gaps 8 and current traverses the corresponding fuse 5, which is fused by the passage of the current through it, the glass supporting strips being shattered thereby, the circuit interrupted, and the continuation of the are at the corresponding spark gap 8 prevented. Only one of the fuses will ordinarily be destroyed at a time and the re mainder Will-serve as additional protection during similar discharges The .masses of the conducting coatings or small almost inappreciable amounts of conducting gases or vapors will be formed When they are fused and no arcs will continue after the discharge.

It may be preferable in some cases to provide for the inclusion in the circuit of only a single fuse at a time and to that end I have provided a device which is shown in F igsi 2 and 3. Suitably supported upon the exterior of a rotatable drumll are a plurality of fuses 12, similar in character. to the fuses 5 of Fig. 1 opposite ends of which are adapted to be engaged by brushes l3 and lei at certain positions of the rotatable drum. The b ush 13 is connected with one terminal films being very 15 of a spark gap ldthe other terminal 17 of which is connected to a distributing conductor 18 and the brush 14 is connected to A stationary stop 19 is provided in the path of movement oi the fuses 12 so that it engages the fuse which is in.

service in order to prevent rotation of. the drum While the active use remains intact. Rotation of the drum may be effected, upon destruction of a fuse, by means of a spiral spring 20,' one end of which is attached to the drum 11 and the other to a stationary shaft 21 upon Whichthc drum 11 is mounted. Upon the occurrence'of a discharge across the spark gap '16 the conducting'film,

' which at that time isengaged by the brushes i3 and M, is fused and the supporting strip is shattered thereby permitting the spring 20 tofactu'ate the drum and bring another strip into engagement with the stop 19 and its conducting film into. engagement with the brushes 13 and 14.

I claim as my invention:

1. An-elcctmcai fuse comprismg'a plate of frangible insulating ins-tonal ,,a film of conducting material covering said plate, the passage of current through said material seirving to destroy it and to fracture said ate.

P 2. An electrical fuse comprising a plate of frangibleinsulating material and a film of fusible conducting material upon its surface, the fusing of whlch fractures said plate.

3. An electrical fuse comprising a plate of frangible insulating material and a film of fusib e conducting material covering its surface, destruction of which, by the passage of current therethrough, also ruptures the plate of insulating material, the mass of the conducting material being so small as to preclude the production of suiiieient amounts of gases or vapors to form a (:01)-

ducting medium after the destruction of the fuse.-

4. An electrical fuse comprising a nonconduetin frangible body and a fusible conductin fi m covering its surface the fusing of which breaks said frangible body and produces only a negligible amount of conducting vapor.

In testimony whereof, I have hereunto subscribed my name this 21st day of August ALEXANDER JAY WUR' S. Witnesses:

HIRAM A. TAYLOR, O'r'ro S. SCHAIRER. 

